The Complete Guide to Muun Pure Nattokinase 2,000 FU
By the Muun team · Reading time: 7 minutes · Last updated: September 2026
In short: Muun Pure Nattokinase is a single-ingredient enzyme supplement: 100 mg of nattokinase from fermented non-GMO soybeans, standardized to 2,000 FU of activity per vegan capsule, with vitamin K2 removed. One capsule a day, 90 capsules per bottle. Take it on an empty stomach with room-temperature water. Not for people who are pregnant, breastfeeding, allergic to soy, living with a bleeding disorder, or taking medication that affects blood clotting. Everything below explains why each of those sentences matters.
A product page gives you a title, a few bullet points and a price. That's enough to buy, but not enough to feel sure about what you're buying, and for a supplement you'll take every day for three months, we think you deserve more. This guide covers the questions we get asked most by email and in our community: what "FU" means, why a nattokinase supplement is different from eating natto, why we removed vitamin K2, how to take an enzyme so it isn't wasted, and how Muun makes and stands behind this product.
Why we made a nattokinase capsule at all
Muun started with body care and feminine care for women who read labels. When we asked our community what they wanted next, the same answer kept coming back: something simple for daily heart-and-circulation wellness that didn't require a chemistry degree to understand.
When we looked at the nattokinase shelf, we saw the opposite of simple. Proprietary blends with undisclosed ratios, "10,000 FU" claims that only worked out if you took three capsules, softgels with gelatin, and labels that listed milligrams but not activity. Some were fine products. But none of them said clearly, on the front, what was inside and how much of it worked.
So the brief for this product was one sentence: one enzyme, one clear potency, one capsule a day, and a label a first-time buyer can read in a minute. Everything below is what that brief turned into.
What is nattokinase?
Nattokinase is an enzyme produced when soybeans are fermented with Bacillus subtilis to make natto, a traditional Japanese food eaten for centuries, usually at breakfast. Researchers isolated the enzyme in the 1980s and named it after the food. It's a protein, not a vitamin, mineral or herb, and that single fact shapes almost everything about how it should be made, labelled and taken.
Because it's an enzyme, the important question isn't just "how much is in the capsule?" but "how much of it is active?" That's where FU comes in.
FU vs mg: reading a nattokinase label properly
Alt: Infographic comparing 100 mg (weight) and 2,000 FU (enzyme activity) on Muun Pure Nattokinase label
Most supplement labels tell you weight in milligrams. For a mineral like magnesium, weight is the whole story. For an enzyme it isn't. Enzymes are measured by what they do, and nattokinase activity is expressed in FU, Fibrinolytic Units, a laboratory measure of how much fibrin the enzyme can break down under standard conditions.
So on the Muun label you'll see two numbers for the same ingredient:
100 mg is the weight of nattokinase powder in each capsule. 2,000 FU is the standardized activity of that powder.
They are not interchangeable, and "2,000 FU" is definitely not "2,000 mg" (or 200 mg; we've seen that version too, and we don't blame anyone, because almost no label explains it). Two products can list the same 100 mg and deliver quite different FU depending on how the enzyme was extracted, purified and stored. That's why the FU figure is the one to compare, and why a label that only shows milligrams is telling you less than it seems.
2,000 FU per capsule is the reference potency used in much of the published nattokinase research and the level you'll see on established brands. We chose it deliberately. Some products now advertise 4,000, 8,000 or 10,000 FU per serving, usually by asking you to take two or three capsules or by bundling in other enzymes. Higher numbers make for bigger fonts on a label; they don't change what the research was actually done with. Muun's position is a clear, honest 2,000 FU, once a day.
Nattokinase supplement vs eating natto: what's the difference?
People sometimes ask why they shouldn't just eat natto. You can, and if you enjoy it, it's a wonderful food. But three things separate the food from the supplement.
Taste and smell. Natto is famously pungent and sticky. Muun capsules are unflavoured, natural ivory in colour, with only a faint fermented-soy scent when you open the bottle. Nothing to chew, nothing to get used to.
Consistency. The enzyme content of natto varies from batch to batch and brand to brand. A standardized supplement gives you the same 2,000 FU every day.
Vitamin K2. This is the big one, and it deserves its own section.
Why Muun Pure Nattokinase is vitamin K2-free
Natto is one of the richest food sources of vitamin K2 (menaquinone-7). That's a benefit for many people, but a concern for one specific group: anyone whose doctor has them on a medication that works by opposing vitamin K. For those people, a sudden change in vitamin K intake can alter how their medication behaves, and they are typically told to keep vitamin K intake steady.
When nattokinase is extracted and purified for a supplement, the vitamin K2 is removed. Muun's capsules contain the enzyme only, and we say so plainly on the front label: Vitamin K2-Free. That's why the search phrase "nattokinase without K2" exists, and why we made sure the answer for our product is clear.
Two honest caveats. First, "K2-free" is about what's not in the capsule; it is not a signal that nattokinase is appropriate alongside blood-thinning medication. Nattokinase itself is a fibrinolytic enzyme, and anyone taking products that affect blood coagulation must speak with their health care practitioner before using it. Second, if you want K2 for bone or other reasons, take it as a separate product on your practitioner's advice, rather than expecting it from a nattokinase capsule.
What's actually in the capsule (and what isn't)
Alt: Product facts label of Muun Pure Nattokinase showing 100 mg nattokinase, 2,000 FU, non-medicinal ingredients and warnings
Medicinal ingredient (per capsule): Nattokinase 100 mg, from fermented non-GMO soybean natto extract, 2,000 FU.
Non-medicinal ingredients: hypromellose (the plant-based capsule shell, in place of gelatin), microcrystalline cellulose, magnesium stearate, gellan gum. That's the complete list. There is no proprietary blend, no serrapeptase, no lumbrokinase, no bromelain, no added vitamin K2, and no artificial colours, flavours or preservatives.
Free of added gluten, nuts, eggs, animal products, dairy, fish or shellfish, starch, wheat and yeast. Contains soy by nature; it is a soy-derived product and not suitable for anyone with a soy allergy.
Suitable for: vegans and vegetarians (gelatin-free capsule), and anyone who prefers a single-ingredient, clean-label supplement they can read in one breath.
Muun's brand line is less is more. We didn't add ingredients to make the label look busier; we kept it to the one enzyme people are actually searching for, at the potency the research used.
How to take nattokinase so it isn't wasted
Alt: Suggested use for Muun Nattokinase 2,000 FU: adults 19+, one capsule daily, with room-temperature water, 30–60 minutes before a meal
Because nattokinase is a protein, it's sensitive to heat and to stomach acid. A few small habits make a real difference.
One capsule a day. Each bottle holds 90 capsules, a full 90-day supply. There's no loading phase and no multi-capsule dose to remember.
On an empty stomach. Take it 30–60 minutes before a meal, or 2 hours after. Many people find first thing in the morning, before breakfast, is the easiest slot to keep consistently.
With a full glass of room-temperature water. This one is not decorative. Taking any capsule on an empty stomach with only a sip of water can leave some people with a mildly unsettled stomach; a full glass solves it for most. Avoid hot coffee, tea or soup at the same time, because heat degrades enzymes. If a full glass still doesn't agree with you, switch to the "two hours after a meal" window instead.
Be consistent, be patient. Nattokinase is a daily-support ingredient, not a quick fix. Give it a full bottle before you judge it.
Store it well. Cool, dry place, away from heat, moisture and direct sunlight. Cap tightly closed.
Who it's for, and who should not take it
Alt: Woman holding Muun Pure Nattokinase bottle beside a list of who the product is for
Muun Pure Nattokinase is made for adults 19 and over who are proactive about daily cardiovascular wellness, who prefer to know exactly what they're taking, and who would rather take one clearly labelled capsule than a complicated enzyme stack. Most of our community are women in their 40s, 50s and 60s who read labels closely; this product was designed with that reader in mind.
Please do not use it if you are pregnant or breastfeeding, if you are allergic to soy, if you have a bleeding disorder, or if you take any product or medication that affects blood coagulation. Consult a health care practitioner before use if you have a cardiovascular, kidney or liver condition, or if you take any medication. Stop use 7 days before scheduled surgery. Keep out of reach of children.
We print these warnings in both English and French on every bottle. We'd rather be the brand that tells you who shouldn't buy than the brand that sells to everyone.
How we make it, and how we stand behind it
Sourcing. The nattokinase is extracted from natto made with non-GMO soybeans, then purified and standardized so that every capsule delivers 2,000 FU. Standardization is the step that turns a food by-product into a supplement you can dose reliably; it's also the step that removes vitamin K2.
Manufacturing. The capsules are produced and bottled in a GMP-certified facility, and every batch is tested for enzyme activity and safety before it is released. GMP (Good Manufacturing Practice) means the facility follows audited procedures for cleanliness, ingredient identity, batch records and quality control, so the 2,000 FU on the label is the 2,000 FU in the capsule, batch after batch.
Labelling. Every bottle shows the medicinal ingredient with both weight and activity (100 mg / 2,000 FU), the complete list of non-medicinal ingredients, allergens, directions and full warnings, in English and French. The QR code on the back takes you to this page. If you can't find something on the label, that's a bug, and we want to hear about it.
Canada and the US. Muun Pure Nattokinase is sold on Amazon.ca and Amazon.com with the same formula and the same bilingual English/French label.
What to expect in your first 90 days
Open the bottle and you'll see 90 natural-ivory capsules, with a faint fermented-soy scent and no taste to speak of. Take one each morning before breakfast with a glass of room-temperature water. Nattokinase is a daily-support enzyme, not something you feel in an afternoon, so the honest advice is to finish the bottle before you decide whether it has a place in your routine. Keep the cap tightly closed and the bottle out of the sun.
If anything about the product surprises you, good or bad, email us. We read every message, and the people who formulated it are the ones replying.
About Muun
Muun is a wellness brand built around women's daily routines: vegan, made with natural ingredients and kept deliberately simple. Pure Nattokinase 2,000 FU joins a range that already includes our pumpkin seed oil softgels, persimmon body wash and soap, turmeric scrub and feminine care, products that thousands of customers across the US and Canada already use every day.
Our brand line is less is more, and the supporting line on this product says the rest: sometimes a simple formula says more.
Contact: hello@muuncare.com · @muuncare on Facebook and Instagram.
Frequently asked questions
What does 2,000 FU mean on a nattokinase label? FU stands for Fibrinolytic Units, the standard laboratory measure of nattokinase enzyme activity. 2,000 FU per capsule is the reference potency used in much of the published nattokinase research. It describes activity, not weight.
Is 2,000 FU the same as 2,000 mg? No. Muun's capsule contains 100 mg of nattokinase by weight, standardized to 2,000 FU of activity. Milligrams measure how much powder is present; FU measures how active that powder is. Compare products by FU, not mg.
Is nattokinase the same as natto? No. Natto is the fermented soybean food; nattokinase is the single enzyme extracted from it. A nattokinase supplement gives you standardized enzyme activity without the taste, smell or vitamin K2 content of the food.
Why is Muun Nattokinase vitamin K2-free? Natto is naturally rich in vitamin K2, but the purification process for the supplement removes it. Muun contains only the nattokinase enzyme, which matters for people who need to keep their vitamin K intake steady. Talk to your practitioner if that's you.
When is the best time to take nattokinase? On an empty stomach: 30–60 minutes before a meal or 2 hours after, with a full glass of room-temperature water. Many people take it first thing in the morning. Avoid taking it with hot drinks.
Who should not take nattokinase? Anyone pregnant or breastfeeding, allergic to soy, with a bleeding disorder, or taking medication or products that affect blood coagulation. Stop 7 days before surgery. Consult a health care practitioner if you have a cardiovascular, kidney or liver condition or take any medication.
Can nattokinase upset my stomach?
A few people notice mild discomfort when they take it on an empty stomach with too little water. A full glass of room-temperature water fixes it for most; if not, take it two hours after a meal instead. Stop and consult your practitioner if discomfort persists.
Is Muun Nattokinase vegan and gluten-free? Yes. The capsule shell is hypromellose (plant-based, no gelatin) and the product is free of added gluten, dairy, eggs, nuts, fish, shellfish, wheat, starch and yeast. It contains soy.
How many capsules are in a bottle and how long does it last? 90 vegan capsules. At the suggested one capsule a day, one bottle is a 90-day supply.
Does it smell or taste like natto? No. The capsules are unflavoured, natural ivory in colour, with only a mild fermented-soy scent and minimal aftertaste.
Is it available in Canada? Yes. Muun Pure Nattokinase 2,000 FU is sold on Amazon.ca with bilingual English/French labelling, and on Amazon.com in the United States.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Always read the label and consult your health care practitioner before starting any supplement.
